/Engine/Source/Runtime/CoreUObject/Public/Misc/PackageName.h
This will recurse over a directory structure looking for packages.
Returns true if any packages have been found, otherwise false
static bool FindPackagesInDirectory ( [TArray](API\Runtime\Core\Containers\TArray)< [FString](API\Runtime\Core\Containers\FString) > & OutPackages, const [FString](API\Runtime\Core\Containers\FString) & RootDir )